Transcriptional response of bovine monocyte-derived macrophages after the infection with different Argentinean Mycobacterium bovis isolates

Abstract

Infection of bovines with Mycobacterium bovis causes important financial hardship in many countries presenting also a risk for humans. M. bovis is known to be adapted to survive and thrive within the intramacrophage environment. In spite of its relevance, at present the information about macrophage expression patterns is scarce, particularly regarding the bovine host. In this study, transcriptomic analysis was used to detect genes differentially expressed in macrophages derived from peripheral blood mononuclear cells at early stages of infection with two Argentinean strains of M. bovis, a virulent and an attenuated strains. The results showed that the number of differentially expressed genes in the cells infected with the virulent strain (5) was significantly lower than those in the cells infected with the attenuated strain (172). Several genes were more strongly expressed in infected macrophages. Among them, we detected encoding transcription factors, anthrax toxin receptor, cell division and apoptosis regulator, ankyrin proteins, cytoskeleton proteins, protein of cell differentiation, and regulators of endocytic traffic of membrane. Quantitative real-time PCR of a selected group of differentially expressed genes confirmed the microarrays results. Altogether, the present results contribute to understanding the mechanisms involved in the early interaction of M. bovis with the bovine macrophage.

Figure 1

Gene expression fold-change differences between PBMC from M. bovis 303 and 534 infected cells and control uninfected cells using RT-qPCR. Relative gene expression was calculated using the 2-DDCt method with E correction, using RNA pol II mRNA expression as reference gene and the uninfected cells condition as the calibrator. The bars indicate the average ratios of infected cells/uninfected cells ±SEM.